Pityriasis rosea was first described by Gibert in 1860, but it was not until 1900 that its recognition as a distinct clinical entity became established. Since then, varying clinical features have been added so that at present the clinical criteria are so elastic that a diagnosis is much more often and more readily reached.

Widal1 described a case of pityriasis rosea which lasted six months, Hallopeau reported a case in which the herald patch preceded the general eruption by two months. In the case described by Allen2 the herald patch was gigantic; it occupied one-half the chest wall.

REPORT OF CASEE. A., aged 63, born in Russia, was first seen on Feb. 10, 1933. Over the right scapular region he presented a lesion which had been present for four months. The lesion was sharply defined and was about the size of a small palm. It was composed